651 research outputs found

    Minimally invasive surgery for spinal fractures due to multiple myeloma

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    Background: Multiple myeloma (MM) presents with spinal lesions in 60% of cases. The combination of osteolytic lesions with multifactorial osteopenia raises specific surgical treatment challenges. Minimally invasive spine surgery (MISS) could be a potential option for MM spinal lesions treatment. Objective: The objective of this study is to evaluate MISS techniques to treat patients presenting with spine fractures due to MM. Methods: Retrospective analysis of consecutive patients with histology-proven pathological fractures caused by MM treated with MISS between 2009 and 2018. We collected the data from the clinical records on epidemiology, topography of spine lesions, surgical techniques, blood loss, operation time, complications, mean in-hospital time, and clinical evolution. Results: Twenty-one patients were studied - 13 males and 8 females, with a mean age of 64 years (range 43-83). Mean preoperative spinal instability neoplastic score was 9.8 ± 6 (range 5-16). All cases had a thoracolumbar location - 15 patients underwent kyphoplasty (KP) or vertebroplasty (VP) and 6 were treated with other more complex procedures. All patients had a reduction of pain and/or analgesic load. Vertebral body height increased by a mean of 2.9 mm after VP/KP. Mean hospital stay was 1.3 days for KP/VP and 5.0 days for other MISS procedures. Three patients had complications. Conclusions: The heterogeneity of techniques used reflected the variety of spine involvement by MM. KP and VP led to shorter hospital stays and less complications, being adequate for lesions without major instability. More complex MISS techniques offer an effective treatment with short delay for starting MM adjuvant treatment.info:eu-repo/semantics/publishedVersio

    Formation of a novel polypyrrole porous phosphate glass ceramic nanocomposite

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    This work is concerned with evidences of a new composite system, formed by in situ polimerization of pyrrole moieties in the copper-exchanged pore surface of LiTi2(PO4)(3) glass ceramic.10216716

    Preparation of the conducting nanocomposites using molded inorganic matrix: fibrous cerium(IV) hydrogenphosphate as a self-supported pyrrole polymerization agent

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    New supported polypyrrole nanocomposites have been prepared and studied in this work. Self-supported sheets of fibrous cerium(IV) hydrogenphosphate (CePf) were used as the inorganic matrix, since the fibrous morphology presented by this material makes molding possible, giving a desired shape to the final polypyrrole/ CePf conducting nanocomposites. The influence of pyrrole concentration on the nanocomposite preparation was studied, as well as the influence of CePf on the polypyrrole characteristics. XRD, Raman, SEM and conductivity measurement data show the conducting polypyrrole coating CePf fibers, yielding self-supported sheets of organic-inorganic conducting nanocomposites.1361378138

    Properties of [Pd2X2(dppm)(2)] (X=Cl, SnCl3, dppm = bis(diphenylphosphino)methane) complexes on porous Vycor glass

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    Porous Vycor glass (PVG) is used as a matrix for immobilization of complexes containing metal-metal bonds: [Pd2Cl2(dppm)(2)], [Pd-2(SnCl3)Cl(dppm)(2)] and [Pd-2(SnCl3)(2)(dppm)(2)]. The high reactivity of the metal-metal bonds in insertion reactions with small molecules such as CO and SO2 is preserved in the pore medium, and is reversible under vacuum. P-31 MAS-NMR and Raman spectra indicate that there is a range of interactions between the glass and the adsorbed molecules as a result of the availability of different groups in the molecules and of the irregular pore topology as well. The static character of the molecules in the restrictive pore environment precludes motions such as flipping of the ring Pd2P4C2 between boat and chair conformations and rotation of the phenyl rings, and the molecules may present a range of conformations.15564064

    Value of Surgery and Nonsurgical Approaches for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

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    OBJECTIVE: Cervical spondylotic myelopathy (CSM) has become a prevalent cause of spinal cord dysfunction among the aging population worldwide. Although great strides have been made in spine surgery in past decades, the optimal timing and surgical strategy to treat CSM have remained controversial. In this article the authors aimed to analyze the current trends in studies of CSM and to summarize the recent advances of surgical techniques in its treatment. METHODS: The PubMed database was searched using the keywords pertaining to CSM in human studies that were published between 1975 and 2018. Analyses of both the bibliometrics and contents, including the types of papers, authors, affiliations and countries, number of patients, and the surgical approaches were conducted. A systematic review of the literature was also performed with emphasis on the diagnosis and treatment of mild CSM. RESULTS: A total of 1008 papers published during the span of 44 years were analyzed. These CSM studies mainly focused on the natural history, diagnosis, and treatment, and only a few prospective randomized trials were reported. For the authors and affiliations, there was a shift of clustering of papers toward Asian countries in the past decades. Regarding the treatment for CSM, there was an exponential growth of surgical series published, and there was a trend toward slightly more anterior than posterior approaches through the past decade. Patients with CSM had increased risks of neurological deterioration or spinal cord injury with nonoperative management. Because surgery might reduce the risks, and early surgery was likely to be correlated with better outcomes, there was a trend toward attention to mildly symptomatic CSM. CONCLUSIONS: There is emerging enthusiasm for research on CSM worldwide, with more publications originating in Asian countries over the past few decades. The surgical management of CSM is evolving continuously toward early and anterior approaches. More prospective investigations on the optimal timing and choices of surgery are therefore needed.info:eu-repo/semantics/publishedVersio

    Interaction of Sodium Titanate Nanotubes with Organic Acids and Base: Chemical, Structural and Morphological Stabilities

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This work reports the interaction of sodium titanate nanotubes (Na-TiNT) with aqueous solutions of benzoic and phenylphosphonic acids and of aniline. The Na-TiNT were obtained from hydrothermal treatment of TiO(2) in aqueous NaOH solution. The results obtained from FTIR, XRD, TEM and elemental analyses showed that the chemical, structural and morphological stability of the nanotubes is related to the medium (acidic or basic) and to the treatment conditions (temperature and contact time). A titanium(IV) alpha-phenylphosphonate phase was obtained from interaction between Na-TiNT and phenylphosphonic acid. The amount and crystallinity of the new phase were dependent of the contact time and temperature, respectively. On the other hand, TiO(2) or proton-rich titanate nanotubes were formed, depending on treatment conditions, from interaction between Na-TiNT and benzoic acid. When Na-TiNT interacted with aniline, no chemical, morphological or compositional change was observed.21713411348Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Synthesis and characterization of alpha-zirconium (IV) hydrogenphosphate containing metallic copper clusters.

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    SYNTHESIS AND CHARACTERIZATION OF alpha-ZIRCONIUM (IV) HYDROGENPHOSPHATE CONTAINING METALLIC COPPER CLUSTERS. The alpha-zirconium (IV) hydroggeriphosphate (alpha-ZrP) has received great attention in the last years due to its properties like ion exchange, intercalation, ionic conductivity and catalytic activity. This work reports a method to produce metallic copper clusters on alpha-ZrP to be used as catalysts in petrochemical processes. It was found that the solids were non-crystalline regardless of the uptake of copper and the reduction. The specific surface area increased as a consequence of the increase of the interlayer distance to accept the copper ions between the layers. During the reduction, big clusters of copper (0,5-11mu) with different sizes and shapes were produced.281464

    Structure characterization and mechanism of growth of PbTe nanocrystals embedded in a silicate glass

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    A nanocomposite consisting of PbTe nanocrystals embedded in a silicate glass was studied by small-angle x-ray scattering during the early stage of isothermal annealing at 793 K. A theoretical function based on a model of spherical PbTe nanocrystals surrounded by a Pb and Te depleted shell fits well to all experimental curves. The time dependences of the nanocrystal radius and size of the depleted shell agree with the prediction of the theory of nucleation and growth by the classical mechanism of atomic diffusion.892

    Electronic properties of FeCl3-adsorbed single-wall carbon nanotubes

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    The structural and electronic properties of FeCl3 interacting with single-wall carbon nanotubes (SWNTs) were investigated by ab initio methods. By using first-principles spin-polarized calculations, we studied the structural and electronic behavior of FeCl3 adsorbed on both semiconducting and metallic SWNTs. It was found that the FeCl3 molecule behaves as an electron acceptor. The binding energy is very small, thus suggesting that the interaction is through a physisorption regime.722
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